Shrinkproofing wool with polycarbonates



United States Patent 3,079,217 I 'noornvo W901. WKTH PQLYC'GNATES Robert E. Whitfield and Lowell A. Milier, Walnut Creek, and William L. Wasiey, Berkeley, Caiih, assignors to the United States of America as represented by the Secretary of Agriculture No Drawing. Filed Apr. 11, 1961, Ser. No. 102,323 17 (Ilaims. (Cl. 8-128) (Granted under Title 35, US. Code (E52), sec. 266) A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

A principal object of this invention is the provision of new methods for shrinkproofing wool. Another object of the invention is the provision of the novel products so produced. Further objects and advantages of the invention will be obvious from the following description wherein parts and percentages are by weight unless otherwise specified.

In the prior art it is suggested that the shrinkage propperties of wool can be improved by applying to the wool fibers a high molecular weight polyamide such as polyliexamethylene adipamide or similar polyamide of the nylon type. This is accomplished in the following manner: The selected polyamide is first converted into soluble form, for example, by forming an N-rnethylol derivative thereof. The N-methylol derivative is applied to the wool and the treated Wool is then immersed in hydrochloric acid whereby the N-methylol polyamide is converted to the unsubstituted polyamide. A primary disadvantage of this known process is that it is cumbersome and inefficient because it requires procurement of a preformed polyamide, conversion of this to a soluble form, and final reconversion to an insoluble form. Particular trouble is encountered in the last step where extended contact with acid is required to insolubilize the coating of N-methylol polyamide. Under this acid treatment is complete, the polyamide will remain soluble and be re moved from the textile when it is washed.

In accordance with this invention, a pro-formed polymer is not used but a polycarbonate is formed in situ on the wool fibers. This is accomplished by serially applying to the Wool the complementary agents required to form the polycarbonate, these agents-in the preferred modification of the inventionbeing dissolved in mutually-immiscible solvents. Thus in a typical embodiment of the invention the wool is first impregnated with an aqueous solution of a diol in salt form and then impregmated with a solution of a bischloroformate in a waterimmiscible solvent such as carbon tetrachloride. Generally, the solutions are applied in the order given above; however, the reverse order gives good results and it is within the ambit of the invention to apply the solutions in either sequence. By serial application of these solutions to the fabric, each fibrous element is coated with a twophase system, for example, an inner layer of diol in water and an outer layer of bischloroformate in water-immiscible solvent. Under these conditions the diol and bischloroformate react almost instantaneously at the interface between the phases, producing in situ on the fibers a high molecular weight, resinous polycarbonate which coats the fibers and renders them shrinkproof. The polymer formed is insoluble so that the shrinkproofing effect is durable; it is retained even after repeated washings with soap and water or detergent and water formulations. A feature of the invention is that the high molecular weight resinous polycarbonates are formed in many cases at ordinary (room) temperature, which is in sharp contrast to the much higher temperatures required in the conventional melt condensations used in preparing such polymers.

As noted above, the treatment in accordance with the invention renders the treated wool essentially shrinkproof so that garments produced from the treated wool may be laundered in conventional soap and water or detergent and water formulations with negligible shrinking or felting. Further, the treated wool or garments prepared therefrom are in the easy-care category in that after washing and tumble drying, they are quite free from wrinkles so that they require only a minor amount of pressing. An important point to be stressed is that the shrinkproofing effect is secured without damage to the hand of the fabric. That is, the treated fabric retains its normal hand so that it is useful for all the conventional applications in fabricating garments as is untreated wool. Other items to be mentioned are that the treatment does not cause any degradation of the wool so that there is no significant loss of tensile strength, abrasion resistance, resiliency, elasticity, etc. Moreover, since the polymer is formed in situ on the fibers-in contrast to systems wherein polymers are spread en masse over the face of a fabric-there is substantially no loss of porosity of the fabric. A further item is that the treated wool may be dyed with conventional wool dyes to obtain brilliant, level dyeings.

A particular feature of the invention and one that emphasizes its simplicity is that no heat-curing step is required. Following application of the two solutions, the textile merely needs to be rinsed or washed. Then, after drying, it is ready for use or sale.

The invention is applicable to wool in any physical form, for example, bulk fibers, slivers, rovings, yarns, felts, woven textiles, knitted textiles, or even completed garments or garment parts.

A remarkable feature of the invention is that the polymers formed on the wool fibers are not merely physical coatings, they are chemically bonded to the wool, that is, the added polymer is grafted to the wool. The mechanism by which the graft polymerization occurs is believed to involve a reaction of functional groups on the bischloroformate with the free amino or hydroxy groups present in the wool molecule, these reactions giving rise to such linkages as urethane or carbonate which chemically unite the wool with the polycarbonate. Thus the polycarbon ates grafter to wool in accordance with the invention can be postulated by the following idealized formulas:

idealized as the polycarbonate chains may be attached at both their ends to a single wool molecule or they may cross-link together ditferent wool molecules through urethane or carbonate linkages. The important point from a practical and realistic view is that chemical bonding of the polycarbonate to the wool has been demonstrated and the theoretical nature of the mechanism of bonding is not of real concern to the invention.

It will be evident from the description herein that the invention is of great latitude and versatility and can be employed for forming on and grafting to wool fibers a wide variety of condensation polymers, particularly and preferably those polymers wherein the recurring structures contain at least one carbonate group, that is, a group of the structure it -z-ozwherein Z is sulphur or oxygen.

GENERAL CONSIDERATIONS In the practice of the invention, selection is first made of the appropriate complementary agentsherein termed Component A and Component B required to form the desired polymer on the wool fibers. The interrelationship between the nature of the agents to be used as Components A and B and the type of polymer produced is explained in detail below in connection with the various modifications of the invention. However, it is apropos to mention at this point that in general, Component A may be a diol or a mixture of different diols and Component B may be a bischloroformate or a mixture of different bischloroformates. Since Components A and B may be selected to form any desired type of polycarbonate, these components may be aptly termed as complementary organic polycarbonate-forming intermediates. They may further be appropriately designated as fast-reacting or direct-acting because they form the resinous polycarbonates rapidly and directly on contact without requiring any aftertreatments, such as treatment with curing agents, oven cures, etc.

Having selected the desired Components A and B, these are formed into separate solutions for application to the Wool to be treated. An essential consideration in the preferred modification of the invention is that the solvents used in the respective solutions of Components A and B be substantially mutually immiscible so that a liquidliquid interface will be set up between the two solutions on the wool fibers. Thus, for example, Component A is dissolved in water and Component B is dissolved in benzene, carbon tetrachloride, toluene, xylene, ethylene, dichloride, chloroform, hexane, octane, petroleum ether or other volatile petroleum distillate, or any other inert, water-immiscible solvent. The two solutions are then applied to the wool serially, that is, the wool is treated first with one solution then with the other. The order of applying the solutions is not critical. Generally, the solution of Component A is applied first and the solution of Component B is applied next; however, the reverse order gives good results and it is within the ambit of the invention to apply the solutions in either sequence.

The solutions may be applied to the wool in any desired way as long as they are applied serially. A preferred method involves immersing the wool in one solution, removing excess liquid as by use of squeeze rolls, immersing the Wool with the second solution, again removing excess liquid, rinsing the treated fabric in water and then drying it. Conventional apparatus consisting of tanks, padding rolls, squeeze rolls and the like are generally used in applying the respective solutions. The amount of each solution applied to the textile may be varied by altering the residence time in the solutions, the pressure exerted by the squeeze rolls and by varying the concentration of the active materials in the respective solutions. To decrease carry-over of the solvent from the first treating solution to the second solution, the wool after its immersion in the first solution may be subjected to drying conditions such as a current of warm air to concentrate the solution carried by the wool.

As noted above, a critical factor in the preferred form of the invention is that the complementary agents-Component A and Component B-are serially applied to the textile dispersed in solvents which are substantially mutually immiscible. The nature of the solvents is of no consequence as long as they are essentially inert and possess the above-stated property of substantially immiscibility. Usually volatile solvents are preferred as they may be removed from the treated textile by evaporation. However, non-volatile solvents can be used, in which case they may be removed from the product by extraction with suitable volatile solvents therefor or washed outwith soap and water or detergent and Water formulations. In many cases the ingredients of Component A are soluble in water and may thus be applied to the textile in aqueous solution. In such case the solvent for Component B may be any inert, essentially water-immiscible organic solvent. Typical illustrative examples thereof are benzene, toluene, xylene, carbon tetrachloride, ethylene dichloride, chloroform, hexane, octane, petroleum ether or other volatile petroleum fraction. It is, however, not essential that Component A be employed in aqueous solution. Thus, one may utilize a system of two essentially immiscible organic solvents, Component A being dispersed in one solvent and Component B in the other. As an example, Component A may be dispersed in 2-bromoethyl acetate and Component B dispersed in benzene. Another example involves using formamide, dimethylformamide, or diethylformamide as the solvent for Component A and using n-hexyl other as the solvent for Component B. A further example involves a system of adiponitrile as the solvent for Component A and ethyl ether as the solvent for Component B. Examples of other pairs of solvents which are substantially immiscible with one another and which may be used for preparing the solutions of the respective reactants are Z-bromoethyl acetate and n-hexyl ether, ethylene glycol diacetate and n-hexyl ether, adiponitrile and n-butyl ether, adiponitrile and carbon tetrachloride, benzonitrile and formamide, n-butyl ether and formamide, di-N-propyl aniline and formamide, isoamyl sulphide and formamide, benzene and formamide, butyl acetate and formamide, benzene and nitromethane, n-butyl ether and nitromethane, carbon tetrachloride and formamide, dimethyl aniline and formamide, ethyl benzoate and formamide.

In cases where Component A is a diol in the form of its alkali-metal salt, the solvents therefor may contain hydroxy groups. Because alcoholate and phenolate groups are so much more reactive than hydroxy groups, there Will be little if any interference by reaction of the hydroxy groups of the solvent with the active agents of Component B, particularly if the solutions of the reactants are at ordinary temperatures. In such event, then, solvent pairs of the fol-lowing types may be employs/.1: Diethylene glycol monomethyl ether and n-hexyl ether, diethylene glycol monoethyl ether and n-hexyl ether, Z-ethylhexanol and adiponitrile, isoaznyl alcohol and adiponitrile, glycerol and acetone, capryl alcohol and forrnarnide, ethylene glycol and benzonitrile, diacctone alcohol and di-N-propylaniline, 2-ethylhexanol and formamide, triethylene glycol and benzyl other.

The concentration of active materials (Component A and Component 3) in the respective solutions is not critical and may be varied widely. Generally, it is preferred that each of the pair of solutions contains about from 1 to 20% of the respective active component. In applying the process of the invention, enough of the respective solutions are applied to the Wool to give a polymer deposit on the fibers of about 1 to 10%. Such amounts provide a substantial degree of shrinkproofing with no significant reduction in hand of the wool. Greater amounts of polymer may be deposited on the fibers if desired but tend to change the natural hand of the wool. Also, thicker deposits are likely to contain substantial amounts of non-grafted polymer. The relative amounts of Component A and Component B applied to the wool may be varied as desired for individual circumstances. Generally, it is preferred to apply the components in equimolar proportions, that is, the amounts are so selected that there are the same number of functional groups provided by Component A as provided by the functional groups of Component B.

It is often desirable to add reaction promoters or catalysts to either of the solutions of Components A or B in order to enhance reaction between the active agents. For example, in cases where the system involves reaction between a diol and a bischloroformate it is desirable to add to either of the solutions, preferably the solution of Component A, a sufiicient amount of alkaline material to take up the HCl formed in the reaction. For such purpose one may use a tertiary amine such as pyridine, dimethyl aniline, or quinoline or an alkali-metal hydroxide, or, more preferably, an alkaline material with buffering capacity such as sodium carbonate, sodium bicarbonate, trisodium phosphate, borax, etc. The reaction of Components A and B may also be catalyzed by addition of such agents as tributyl tin chloride, stannous tartrate, ferric chloride, titanium tetrachloride, boron trifluoride-diethyl other complex, or tin salts of fat acids such as tin laurate, myristate, etc.

Where one of the solutions of the reactants contains water as the solvent, it is often desirable to incorporate a minor proportion of a surface-active agent to aid in dispersing the reactant and to assist in penetration of the solution into the textile. For this purpose one may use such agents as sodium alkyl (C -C sulphates, the sodium alkane (C -C sulphonates, the sodium alkyl (C C benzene sulphonates, esters of sulphosuccinic acid such as sodium dioctylsnlp'nosuccinate, and soaps, typically sodium salts of fat acids. Emulsifying agents of the non-ionic type are suitable, for example, the reaction products of ethylene oxide with fatty acids, with polyhydric alcohols, with partial esters of fatty acids and polyhydric alcohols or with alkyl phenols, etc. Typical of such agents are a polyoxyethylene stearate containing about 20 oxyethylene groups per mole, a polyoxyethylene ether or sorbitan monolaurate containing about 16 oxyethylene groups per mole, a distearate of polyoxyethylene ether or sorbitol containing about 40 oxyethylene groups per mole, iso-octyl phenyl ether of polyethylene glycol, etc. Generally, only a small proportion of surface-active agent is used, on the order of 0.05 to 0.5%, based on the weight of the solution. In addition to, or in place of the surface-active agent, a supplementary solvent may be added to the primary solvent (water) in quantity SUlfiClfil'li'. to disperse the active reactant. For such purpose one may employ acetone, or other inert, volatile solvent, particularly one that is at least partially miscible with water. It is evident that the solutions of Components A and B need not necessarily be true solutions; they may be colloidal solutions, emulsions, or suspensions, all these being considered as solutions for the purposes of the present invention.

Ordinarily, the treatment of the wool with the solutions of the complementary agents is carried out at room temperature (particularly where the diol is used in salt form) as at such temeprature the polymerization takes place very rapidly, that is, in a matter of a minute or less. If, however, a higher rate of polymerization is desiredas in continuous operation on long lengths of cloththe second solution may be kept hot, for example, at a temperature up to around 150 C. Also, where the agents used include a diol as such (in contrast to the alkali salt thereof) it is preferable to heat the second solution as the polymerization rates with the diols are generally unsatisfactory at room temperature.

As has been explained above, in the preferred modification of the invention the solutions of Components A and Bthe complementary condensation polymer-forming intermediates-are serially applied to the woo-l in the form of mutually-immiscible solutions to provide a liquidthe invention, a system is used which utilizes a solidliquid interface. Such a system is established in the following Way: The wool is first impregnated with a solution of one of the complementary agents-for example, Component A-dispersed in an inert, volatile solvent. The Wool is then subjected to drying as by subjecting it to a current of hot air. :The Wool fibers which are now covered with a deposit of the first component in a solid state, are then impregnated with the complementary agentComponent B, in this case, dispersed in an inert, preferably volatile solvent. In this way the fibers are layered with a superposed system of solid Component A and a solution of Component B. Under these conditions polymerization takes place rapidly forming the polymer in situ on the fibers and grafted thereto. In this system it is not essential that the respective solvents be immiscible. Thus, for example, Component A may be applied in water solution and Component 3 in a water-miscible solvent such as dioxane or acetone. A typical example of practicing this modification involves immersing the wool in an aqueous solution of a diol in salt form, removing the wool from the solution, squeezing it through rolls to remove excess liquid, subjecting it to a draft of hot air until the wool is dry to the touch (about 10-20% moisture in the impregnated wool) and then immersing the wool in a solution of a bischloroforrnate dissolved in an inert, volatile solvent. The wool is then removed from this second bath, squeezed through rollers to remove excess water, rinsed, and dried in air. Although this system is operative, it is not a preferred technique because the polymerization at the solid-liquid interface is slower and less uniform in degree of polymerization and the degree of shrinkproofing afforded to the wool per unit Weight of polymer formed on the fibers is less than with the system of mutually-immiscible solutions.

COMPONENTS A AND B As noted briefly above, the selection of Components A and B depends on the type of polymer desired to be formed on the Wool fiber and grafted thereto. Typical examples of compounds which can be employed as Cornponent A in a practice of the invention are described below.

As the diol one may employ any of the aliphatic, aromatic, or heterocyclic compounds containing two hydroxy groups, preferably separated by at least two carbon atoms. The diols may be substituted if desired with various noninterfering (not-functional) substituents such as ether groups, sulphone groups, tertiary amine groups, thioether groups, fluorine atoms, etc. Typical compounds which may be used are listed below merely by way of illustration and not limitation: Ethylene glycol, diethylene glycol, 2,2- dimethyl propane-1,3-diol, propane-1,3-diol, butane-1,4- diol, hexane-1,6-diol, octane-1,8-diol, decane-1,l0-diol, dodecane-1,l2-diol, butane-1,2-diol, hexane-1,2-diol, 1-O- methyl glycerol, Z-O-methyl glycerol, cyclohexane-l,4- diol, hydroquinone, resorcinol, catechol, bis (parahydroxyphenyl) methane, 1,2-bis(parahydroxyphenyl) ethane, 2- 2-bis(parahydroxyphenyl) propane, 2,2-bis(parahydr0xyphenyl) butane, 4,4dihydroxybenzophenone, naphthalene-1,5-diol, biphenyl-4,4'-diol, 2,2-bis(3-methyl-4-hydroxyphenyl) propane, 2,2-bis(3isopropyl-4-hydroxyphenyl) propane, 2,2-bis(4hydroxy-dibromophenyl) proliquid interface between the solutions as they are serially I laid onto the fibers. In a less preferred modification of pane, etc.

If desired, mixtures of different diols may be used. It is also within the purview of the invention, though less preferred, to use the compounds containing more than two hydroxy groups as for example, glycerol, diglycerol, hexanetriol, pentaerythritol, etc. Moreover, it is within the spirit of the invention to utilize the sulphur analogues of the diols. Thus, for example, instead of using the compounds containing two hydroxy groups one can use the analogues containing either (a) two SH groups or (b one SH group and one OH group.

Among the preferred compounds are the aliphatic diols, for example, those of the type:

wherein n has a value from 2 to 12. Another preferred category of aliphatic compounds are the polyethylene glycols, i.e.:

wherein n has a value from zero to 10. A preferred category of aromatic diols are the bisphenols, that is, compounds of the type R! E R! wherein RCR represents an aliphatic hydrocarbon group containing 1 to 12 carbon atoms and R represents hydrogen or a lower alkyl radical. In this category especially preferred compounds are 2,2-bis(parahydroxyphenyl) propane, often designated as bisphenol-A; 2,2- bis(3-methyl-4-hydroxyphenyl) propane; 2,2-bis(3-isopropyli-hydroxyphenyl) propane; and brominated derivatives of bisphenol A, such as 2,2-bis(4-hydroxy-dibromophenyl) propane.

The diols are employed as such or in the form of their alkali-metal salts, that is, as alcoholates or phenolates, depending on whether the diols are aliphatic or aromatic. The alkali-metal derivatives are preferred as they will react with the active agents of Component B at room temperature. Withthe diols, as such, temperatures above room temperature are generally required to promote reaction with their complements in Component B. In such case proper temperature for the reaction can be achieved by holding the second solution into which the textile is immersed, at about 56 to 150 C. it is obvious that the solvent selected for'the second solution will need to be one which has a boiling point above the temperature selected, or, in the alternative, a pressurized system can be used to maintain the solvent in the liquid phase.

In the modification of the invention wherein water is used as the solvent for Component A (a diol in this case) and Component B is dispersed in a water-immiscible, inert solvent, it is preferred to use aromatic diols in their salt (phenolate) form. This affords several distinct advantages. Thus the alkali-metal phenolates are quite soluble in water, they are relatively stable in aqueous solution (in contrast to the alcoholates), and they will react at room temperature with bischloroformates so that no heating is required.

Typical examples of compounds which can be employed as Component B in a practice of the invention are described below.

As the bischloroformate one may use any of the aliphatic, aromatic, or heterocyclic compounds containing two chloroformate groups Ethylene glycol bischloroformate,

diethylene glycol bischloroformate, 2,2-dimethyl propane 1,3-diol bischloroformate, propane-1,3-diol bischloroformate, butane-1,4-diol bischloroformate, hexane-1,6-diol bischloroformate, octane-1,8-diol bischloroformate, decane-LlO-diol bischloroformate, butane-1,2-diol bischloroformate,

hexane-1,2-diol bischloroformate, Z-methoxyglycerol-1,3-bischloroformate, glycerol-1,2-bischloroformate, glycerol-1,3-bischloroformate,

diglycerol bischloroformate,

hexanetriol bischloroformate,

pentaerythritol bischloroformate,

cyclohexaue-l,4-diol bischloroformate,

hydroquinone bischloroformate,

resorcinol bischloroformate,

catechol bischloroformate,

bischioroformate of 2,Z-bis(parahydrcxyphenyl) propane, bischloroformate of 2,2-bis(parahydroxyphenyl) butane, bischloroformate of 4,4-dihydroxybenzophenone, bischloroformate of 1,2-bis(parahydroxyphenyl) ethane, naphthalene-LS-diol bischloroformate,

biphenyl-4,4'-diol bischloroformate, etc.

If desired, mixtures of difierent bischloroformates may be used.

Among the preferred compounds are the aliphatic bischloroformates, for example, those of the type:

ii if ClCO (CH2)n 'OCO1 wherein n has a value from 2 to 12. Another preferred category of compounds are the bis-chioroformates derived from polyethylene glycois, e.g.,

ti ll ClCOCH CH2[O CHz-CHzlm-O 0Hz0t1z-0 001 wherein n has a value from zero to 10. A useful category of aromatic bischloroformates are the bisphenol chloroformates, that is, compounds of the type:

R R R' t -iit 01-00 B 00-01 wherein R-CR represents an aliphatic hydrocarbon group containing 1 to 12 carbon atoms and R is hydrogen or a low alkyl radical.

It is also evident that the sulphur analogues of the bischloroformates may be used and such are included within the spirit of the invention. Thus, instead of using the compounds containing two groups one may use any of the compounds containing the sulphur analogues of these groups, for example, the compounds containing two groups of the formula wherein one X is sulphur and the other is oxygen or wherein both Xs are sulphur. Moreover, although the bichloroformates are preferred because they are reactive and relatively inexpensive, it is not essential that they contain chlorine and one may use the corresponding bisbromoformates or bisiodoformates.

Numerous variations in the basic procedure herein described Will suggest themselves to those skilled in the art in the application of the invention without departing from the fundamentals thereof. Some of these variations are explained below.

If desired, one may prepare a prepolyrner containing internal carbonate units and terminal hydroxy groups. Such prepolymers can be prepared, for example, in known manner by reacting a molar excess of diol with a hischioroformate. The prepolymer would then be used as Component A while for Component B one would use a bischloroformate. A typical example in this area would be to use as Component A a prepolymer of the typeand to use as Component B a bischloroformate (ClCOOR' COoCl) thus to produce a polycarbonate containing repeating units of the type- (In these formulas, R, R, and R represent organic radicals.)

In the alternative, one may prepare a prepolyrner con taining internal carbonate units and terminal OCOC1 groups. Such a prepolymer used as Component B in conjunction with a diol as Component A would yield a polycarbonate similar to that shown above.

It is evident from the above description that there is a very wide choice available in the selection of the complementary agents so that generically the polycarbonates deposited onto the wool and grafted thereto will contain repeating units of the type-- Examples The invention is further demonstrated by the following illustrative examples.

Standard shrinkage test: The tests for shrinkage referred to below were conducted in the following way: The wool samples were milled at 1700 rpm. of 2 minutes at 4042 C. in an Accelerotor with 0.5% sodium oleate solution, using a liquor-to-wool ratio of 50 to 1. After this washing operation the samples were measured to determine their area and the shrinkage was calculated from the original area. With this washing method, samples of control (untreated) wool gave an area shrinkage of 45%. The Accelerotor is described in the American Dyestufi Reporter, vol. 45, p. 685, Sept. 10, 1956.

EXAMPLE 1 A sample of wool cloth was immersed for 60 seconds in a 6% solution of the sodium salt of 2,2bis(3-methyl 4-hydroxyphenyl) propane in water. The cloth was run through squeeze rolls to remove excess liquid, then immersed for 60 seconds in a solution containing 5 parts by volume of the bischlorotormate of hexane-1,6-diol dissolved in 100 parts by volume of a petroleum solvent containing 96% aromatics, 1% parafiins, and 3% napthenes, specific gravity 0.87, boiling range 314362 F. The cloth was run through squeeze rolls to remove excess liquid, rinsed with water, and dried in air.

The treated wool had a polycarbonate resin uptake of 4.2% and on washing exhibited an area shrinkage of 20%.

EXAMPLE 2 The procedure of Example 1 was repeated with the xception that the second treatment solution contained 5 parts by volume of the bischloroformate of 2,2-dimethyl-propanediol-1,3 in 100 parts by volume of the petroleum solvent.

The treated wool had a polycarbonate resin uptake of 10 3.6% and on washing exhibited an area shrinkage of 23.5%.

EXAMPLE 3 A sample of wool cloth was immersed for 60 seconds in a 6% solution of the sodium salt of 2,2-bis(3-isopropyl- 4-hydroxyphenyl) propane in Water. The cloth was run through squeeze rolls to remove excess liquid, then immersed for 60 seconds in a solution containing 5 parts by volume of the bischloroformate of 2,2-dimethy1-pro panediol-1,3 in parts by volume of the petroleum solvent described in Example 1. The cloth was run through squeeze rolls to remove excess liquid, rinsed with water, and dried in air.

The treated wool had a polycarbonate resin uptake of 2.8% and on washing exhibited an area shrinkage of 27%.

EXAMPLE 4 A sample of wool cloth was immersed for 60 seconds in a 6% solution of the sodium salt of 2,2-bis(4-hydroxyphenyl) propane in water. The cloth was run through squeeze rolls to remove excess liquid, then immersed for 60 seconds in a solution containing 5 parts by volume of the bischloroformate of hexane-1,6-diol dissolved in 100 parts by volume of benzene. The cloth was run through squeeze rolls to remove excess liquid, rinsed with water, and dried in air.

The treated wool had a polycarbonate resin uptake of 1.3% and on washing exhibited an area shrinkage of 20%.

This invention is a continuation-in-part of our copending application Serial No. 98,718, filed March 27, 1961, entitled Shrinkproofing Wool With Polymers, wherein is disclosed the broad concept of grafting condensation polymersparticularly polyamidest0 wool. Said application is a continuation-in-part of the following applications: Ser. No. 90,604, filed February 20, 1961, entitled Shrinkproofing of Wool With Polyarnides (which in turn is a continuation-in-part of Ser. No. 22,651, filed Apr. 15, 1960); Ser. No. 83,848, filed Ian. 19, 1961, entitled Shrinkproofing of Wool With Polyurethanes; Ser. No. 85,438, filed Ian. 27, 1961, entitled Shrinkprooiing of Wool With Polyureas; Ser. No. 88,232, filed February 9, 1961, entitled Shrinkprooiing of Wool With Polyesters; and Ser. No. 88,233, filed February 9, 1961, entitled Shrinkproofing of Wool With Polycarbonates. Of the applications referred to above, the following have been abandoned: Serial No. 22,651, Serial No. 83,848, Serial No. 85,438, Serial No. 88,232, Serial No. 88,233, and Serial No. 90,604.

Attention is called to the fact that the present application is one of a series of applications filed by us generally concerned with shrinkproofing wool wherein various types of condensation polymers are formed on and grafted to the wool fibers. Polycarbonates are the subject of the present application; polyurethanes are the subject of Ser. No. 99,319, filed March 29, 1961; polyureas are the subject of Ser. No. 100,476, filed April 3, 1961; polyesters are the subject of Ser. No. 101,599, filed April 7, 1961; interpolyrners are the subject of Ser. No. 109,229, filed May 10, 1961. Condensation polymers broadly and polyamides specifically are the subjects of the parent application referred to above, of which this application is a continuation-in-part.

Although the present invention finds its greatest field of utility in the shrinkproofing of wool and is peculiarly adapted for such use because of a combination of important factorsincluding the advantages that a high degree of shrink resistance is imparted with a minor amount of polymer, that the shrinkproofing treatment does not significantly impair the hand of the wool, that the treatment does not impair other desirable fiber characteristics such as tensile strength, elasticity, porosity, etc., that the polymer is grafted to the wool molecules so that the shrinkprooting effect is exceedingly durable and is retained even after long wear and repeated launderingit is evident that the invention may be extended to other areas.

Thus the principles or" the invention may be extended to forming polymers in situ on other substrates besides wool, particularly substrates of a fibrous structure. Typical examples of such materials are animal hides, leather; animal hair; cotton; hemp; jute; rarnie; flax; wood; paper; synthetic cellulosic fibers such as viscose, cellulose acctate, cellulose acctate-butyrate; casein fibers; polyvinyl alcohol-protein fibers; alginic fibers; glass fibers; asbestos; and organic non-cellulosic fibers such as poly (ethylene glycol terephthalate), polyacrylonitr-ile, polyethylene, polyvinyl chloride, polyvinylidene chloride, etc. Such appli' cations of the teachings of the invention may be for the purposes of obtaining functional or decorative effects such as sizing, finishing, increasing gloss or transparency, increasing water-repellancy, increasing adhesionor bonding-characteristics of the substrates with rubber, polyester resins, etc. It is not claimed that in such extensions of our teachings shrinltproofing would be attained nor that graft polymers would be produced. However, it might be expected that graft polymers would be formed with proteinous substrates such as animal hair, animal hides, and the like.

Having thus described the invention, what is claimed is:

1. A process for shrinltproofing wool without signifi cant impairment of its hand which comprises serially impregnating wool with two solutions, one solution containing a diol dispersed in water, the other solution containing a bischloroforrnate dispersed in an inert, volatile, essentially water-imiscible solvent, the said diol and hischloroformate reacting to form in situ on the wool fibers a resinous polycarbonate.

2. The process of claim 1 wherein the diol has the formula HO(CH ),,OH where n has a value from 2 to 12.

3. The process of claim 1 wherein the diol is an aromatic diol.

4. The process of claim 1 wherein the bischlorotormate has the formula- Q Olii-0-R0-i0l wherein R is the group --(Cl-I in which n has a value from 2 to 12.

5. The process of claim 1 wherein the bischloroforrnate is the bischloroformate of an aromatic diol.

6. A process for shrinkproofing wool without significant impairment of its hand which comprises serially impregnating wool with two solutions, one solution containing a diol in a first solvent, the other solution containing 21 biscnloroformate in a second solvent, said first and second solvents being substantially mutually immiscible, the said dic-l and bischlorot-orrnate reacting to form in situ on the wool fibers a resinous polycarbonate.

7. A modified wool fiber which exhibits improved shrinkage properties as compared with the unmodified wool fiber comprising wool fiber having a polycarbonate formed in situ thereon and grafted to the wool.

8. A modified wool fiber which exhibits improved shrinkage properties as compared with the unmodified wool fiber comprising wool fiber having a polycarbonate formed in situ thereon and chemically bonded to the wool,

said polycarbonate containing recurring structural units of the formulai -0-R o-b-o-R'-o-o in which R and R are bivalent organic radicals.

9. The product of claim 8 in which R is --(CH wherein n has a value of 2 to 12.

10. The product of claim 8 in which R is a bivalent aromatic radical.

11. The product of claim in which 'R is (CH wherein n has a value of 2 to 12.

12. The product of claim 8 in which R is a bivalent aromatic radical.

13. A process for treating a fibrous material which comprises applying serially to said material in interfacial relationship, a pair of complementary direct-acting organic polycarbonate-forming intermediates.

14. A process for treating a fibrous material which comprises serially applying to said material a pair of complementary direct-acting organic polycarbonate-forming intermediates in separate phases of limited mutual solubility.

15. A process for treating a fibrous material which comprises serially distributing on the surface of the fibrous elements of said material a pair of complementary directacting organic polycarbonate-forming intermediates in superposed phases of limited mutual solubility, the said intermediates reacting under such conditions to form a polymer in situ on said fibrous elements.

16. A process for treating wool which comprises distributing on the surface of the wool fibers a pair of complementary direct-acting organic polycarbonate-forming intermediates in superposed liquid phases of limited mutual solubility, said intermediates reacting rapidly under said conditions to form a polymer in situ on said fibrous elements and grafted thereto.

17. A process for treating a fibrous material which comprises serially impregnating a fibrous material with two solutions, one solution containing one member of a pair of complementary, direct-acting, organic, polycarbonate-forming intermediates in a first solvent, the other solution containing the complementary member of said pair of complementary, direct-acting, organic, polycarbonate-forming intermediates in a second solvent, said first and second solvents being substantially mutually immiscible, the said pair of intermediates reacting rapidly under said conditions to form in situ on the fibers a resinous polycarbonate.

References fitted in the file of this patent UNITED srArns PATENTS 2,186,889 Ulrich Jan. 9, 1940 2,518,267 Baird Aug. 8, 1950 2,789,964 Reynolds Apr. 23, 1957 OTHER REFERENCES Barr et al.: J. Soc. Dyes and Colourists, November 1946, pp. 338345.

Morgan: Soc. Plastic Engineers, June 1959, pp. 485- 495. 

17. A PROCESS FOR TREATING A FIBROUS MATERIAL WHICH COMPRISES SERIALLY IMPREGNATING A FIBROUS MATERIAL WITH TWO SOLUTIONS, ONE SOLUTION CONTAINING ONE MEMBER OF A PAIR OF COMPLEMENTARY, DIRECT-ACTING, ORGANIC, POLYCARBONATE-FORMING INTERMEDIATES IN A FIRST SOLVENT, THE OTHER SOLUTION CONTAINING THE COMPLEMENTARY MEMBER OF SAID PAIR OF COMPLEMENTARY, DIRECT-ACTING, ORGANIC, POLYCARBONATE-FORMING INTERMEDIATES IN A SECOND SOLVENT, SAID FIRST AND SECOND SOLVENTS BEING SUBSTANTIALLY MUTUALLY IMMISCIBLE, THE SAID PAIR OF INTERMEDIATES REACTING RAPIDLY UNDER SAID CONDITIONS TO FORM IN SITU ON THE FIBERS A RESINOUS POLYCARBONATE. 